Bart Jongejan


2020

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Automatic Detection and Classification of Head Movements in Face-to-Face Conversations
Patrizia Paggio | Manex Agirrezabal | Bart Jongejan | Costanza Navarretta
Proceedings of LREC2020 Workshop "People in language, vision and the mind" (ONION2020)

This paper presents an approach to automatic head movement detection and classification in data from a corpus of video-recorded face-to-face conversations in Danish involving 12 different speakers. A number of classifiers were trained with different combinations of visual, acoustic and word features and tested in a leave-one-out cross validation scenario. The visual movement features were extracted from the raw video data using OpenPose, and the acoustic ones using Praat. The best results were obtained by a Multilayer Perceptron classifier, which reached an average 0.68 F1 score across the 12 speakers for head movement detection, and 0.40 for head movement classification given four different classes. In both cases, the classifier outperformed a simple most frequent class baseline as well as a more advanced baseline only relying on velocity features.

2017

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Automatic identification of head movements in video-recorded conversations: can words help?
Patrizia Paggio | Costanza Navarretta | Bart Jongejan
Proceedings of the Sixth Workshop on Vision and Language

We present an approach where an SVM classifier learns to classify head movements based on measurements of velocity, acceleration, and the third derivative of position with respect to time, jerk. Consequently, annotations of head movements are added to new video data. The results of the automatic annotation are evaluated against manual annotations in the same data and show an accuracy of 68% with respect to these. The results also show that using jerk improves accuracy. We then conduct an investigation of the overlap between temporal sequences classified as either movement or non-movement and the speech stream of the person performing the gesture. The statistics derived from this analysis show that using word features may help increase the accuracy of the model.

2016

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Implementation of a Workflow Management System for Non-Expert Users
Bart Jongejan
Proceedings of the Workshop on Language Technology Resources and Tools for Digital Humanities (LT4DH)

In the Danish CLARIN-DK infrastructure, chaining language technology (LT) tools into a workflow is easy even for a non-expert user, because she only needs to specify the input and the desired output of the workflow. With this information and the registered input and output profiles of the available tools, the CLARIN-DK workflow management system (WMS) computes combinations of tools that will give the desired result. This advanced functionality was originally not envisaged, but came within reach by writing the WMS partly in Java and partly in a programming language for symbolic computation, Bracmat. Handling LT tool profiles, including the computation of workflows, is easier with Bracmat’s language constructs for tree pattern matching and tree construction than with the language constructs offered by mainstream programming languages.

2012

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Automatic annotation of head velocity and acceleration in Anvil
Bart Jongejan
Proceedings of the Eighth International Conference on Language Resources and Evaluation (LREC'12)

We describe an automatic face tracker plugin for the ANVIL annotation tool. The face tracker produces data for velocity and for acceleration in two dimensions. We compare annotations generated by the face tracking algorithm with independently made manual annotations for head movements. The annotations are a useful supplement to manual annotations and may help human annotators to quickly and reliably determine onset of head movements and to suggest which kind of head movement is taking place.

2010

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Incorporating Speech Synthesis in the Development of a Mobile Platform for e-learning.
Justus Roux | Pieter Scholtz | Daleen Klop | Claus Povlsen | Bart Jongejan | Asta Magnusdottir
Proceedings of the Seventh International Conference on Language Resources and Evaluation (LREC'10)

This presentation and accompanying demonstration focuses on the development of a mobile platform for e-learning purposes with enhanced text-to-speech capabilities. It reports on an international consortium project entitled Mobile E-learning for Africa (MELFA), which includes a reading and literacy training component, particularly focusing on an African language, isiXhosa. The high penetration rate of mobile phones within the African continent has created new opportunities for delivering various kinds of information, including e-learning material to communities that have not had appropriate infrastructures. Aspects of the mobile platform development are described paying attention to basic functionalities of the user interface, as well as to the underlying web technologies involved. Some of the main features of the literacy training module are described, such as grapheme-sound correspondence, syllabification-sound relationships, varying tempo of presentation. A particular point is made for using HMM (HTS) synthesis in this case, as it seems to be very appropriate for less resourced languages.

2009

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Automatic training of lemmatization rules that handle morphological changes in pre-, in- and suffixes alike
Bart Jongejan | Hercules Dalianis
Proceedings of the Joint Conference of the 47th Annual Meeting of the ACL and the 4th International Joint Conference on Natural Language Processing of the AFNLP

2008

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Experiments to Investigate the Connection between Case Distribution and Topical Relevance of Search Terms in an Information Retrieval Setting
Jussi Karlgren | Hercules Dalianis | Bart Jongejan
Proceedings of the Sixth International Conference on Language Resources and Evaluation (LREC'08)

We have performed a set of experiments made to investigate the utility of morphological analysis to improve retrieval of documents written in languages with relatively large morphological variation in a practical commercial setting, using the SiteSeeker search system developed and marketed by Euroling Ab. The objective of the experiments was to evaluate different lemmatisers and stemmers to determine which would be the most practical for the task at hand: highly interactive, relatively high precision web searches in commercial customer-oriented document collections. This paper gives an overview of some of the results for Finnish and German, and describes specifically one experiment designed to investigate the case distribution of nouns in a highly inflectional language (Finnish) and the topicality of the nouns in target texts. We find that topical nouns taken from queries are distributed differently over relevant and non-relevant documents depending on their grammatical case.

2006

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Hand-crafted versus Machine-learned Inflectional Rules: The Euroling-SiteSeeker Stemmer and CST’s Lemmatiser
Hercules Dalianis | Bart Jongejan
Proceedings of the Fifth International Conference on Language Resources and Evaluation (LREC’06)

The Euroling stemmer is developed for a commercial web site and intranet search engine called SiteSeeker. SiteSeeker is basically used in the Swedish domain but to some extent also for the English domain. CST's lemmatiser comes from the Center for Language Technology, University of Copenhagen and was originally developed as a research prototype to create lemmatisation rules from training data. In this paper we compare the performance of the stemmer that uses handcrafted rules for Swedish, Danish and Norwegian as well one stemmer for Greek with CST's lemmatiser that uses training data to extract lemmatisation rules for Swedish, Danish, Norwegian and Greek. The performances of the two approaches are about the same with around 10 percent errors. The handcrafted rule based stemmer techniques are easy to get started with if the programmer has the proper linguistic knowledge. The machine trained sets of lemmatisation rules are very easy to produce without having linguistic knowledge given that one has correct training data.

2004

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Corporate Voice, Tone of Voice and Controlled Language Techniques
Lina Henriksen | Bart Jongejan | Bente Maegaard
Proceedings of the Fourth International Conference on Language Resources and Evaluation (LREC’04)